UN R54 Supplement 27 (00 series) · UNECE Regulation No. 54 (ECE R54) — Uniform provisions concerning the approval of pneumatic tyres for commercial vehicles and their trailers.
UN R54 — Supplement 27 to the 00 series of amendments
Supplement 26 → 27
- What changed
- For tyres identified by the "tyre to rim fitment configuration" symbol "A", new paragraph 6.1.4.2.1. sets the maximum overall width in the lower area. It equals the nominal width of the mounting rim, as shown by the manufacturer in the descriptive note, increased by 38 mm. Before, paragraph 6.1.4.3. gave the overall width in the lower area as the rim width increased by 27 mm.
- Annex 9 items 4.1. and 4.2. add the technical service and, where applicable, test laboratory approved for purposes of approval or of verification of conformity. They also add the date and number of the report issued by that service.
- Why
- The width change is to explicitly specify that the maximum overall width of symbol "A" tyres includes a 4 per cent tolerance.
- The Annex 9 change is to align Annex 9 with Annex 1 and to let type approval authorities make the connection with the relevant reports.
Q1What changed9 changes
Maximum overall width of symbol "A" tyres (para. 6.1.4.2.1.)
New paragraph 6.1.4.2.1. applies to tyres identified by the "tyre to rim fitment configuration" (see paragraph 2.20.5.) symbol "A". For these tyres, the maximum overall width in the lower area of the tyre equals the nominal width of the rim, increased by 38 mm. The rim is the rim on which the tyre is mounted, as shown by the manufacturer in the descriptive note. Before, paragraph 6.1.4.3. said that the overall width of these tyres, in the lower area, equals this rim width increased by 27 mm. Paragraph 6.1.4.3. is deleted.
Technical service and report details in Annex 9 (items 4.1. and 4.2.)
In Annex 9, the Original tyre item (4.1.) and the Upgraded tyre item (4.2.) now each have three new lines. The first line asks for the technical service and, where applicable, test laboratory approved for purposes of approval or of verification of conformity. The other two lines ask for the date and the number of the report issued by that service. In item 4.1., the approval line now reads "Approval No. Pursuant to Regulation UN No. 54.". Before, it read "Approval No. pursuant to UN Regulation No. 54.".
Q2Why it changed
- Proposed by
- Expert from France
- Working party
- GRBP, 78th session (August–September 2023) and 79th session (February 2024)
Reasons
The width change is required to explicitly specify that the maximum overall width of symbol "A" tyres includes a 4 per cent tolerance.
Sources (2)
“This amendment to UN Regulation No. 54 is required in order to explicitly specify that the maximum overall width of tyres identified by the “tyre to rim fitment configuration” symbol “A” includes a 4 per cent tolerance.”
“presented a proposal that specified a tolerance for the maximum overall width of tyres identified by the “tyre to rim fitment configuration” symbol A”
The Annex 9 change is required to align Annex 9 with Annex 1 (see Annex 1, paragraphs 5., 6. and 7.). It is also required to allow the type approval authorities to make the connection with the relevant reports.
Sources (2)
“required in order to align Annex 9 with Annex 1 (see Annex 1, paragraphs 5., 6. and 7.) and to allow the type approval authorities to make the connection with the relevant reports.”
“The expert from France proposed aligning annex 9 with annex 1”
Document trail
- 2023-06ProposalECE/TRANS/WP.29/GRBP/2023/18Proposal by the expert from France on the width of symbol "A" tyres
- —Working party adoptsECE/TRANS/WP.29/GRBP/76GRBP 78th session report, para. 18
- 2023-11ProposalECE/TRANS/WP.29/GRBP/2024/14Proposal by the expert from France to align Annex 9 with Annex 1
- —Working party adoptsECE/TRANS/WP.29/GRBP/77GRBP 79th session report, para. 18 (decision to combine with draft Supplement 27)
- 2024-04Sent to WP.29ECE/TRANS/WP.29/2024/2/Rev.1Text that GRBP sent to WP.29 and AC.1
- 2024-06WP.29 adoptsECE/TRANS/WP.29/1179Adopted at the 193rd session (session report, para. 162)
- 2025-01-10In forceC.N.42.2025.TREATIES-XI.B.16.54UN depositary notification
Q3Who is affected
Vehicle manufacturer
- No direct action for this role.
Component supplier
- When you complete Annex 9, give the technical service (and, where applicable, test laboratory) and its report date and number.
Technical service / Approval authority
- For symbol "A" tyres, use nominal rim width plus 38 mm as the maximum lower-area overall width (para. 6.1.4.2.1.).
See every change side by side
RegVault customers compare every version of UN regulations, read the consolidated text and download the PDF.
ⓘ This report gives advice only. It is not legal or type-approval advice.